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arXiv · 2410.17314

Topological excitations at time vortices in periodically driven systems

Gilad Kishony·Ori Grossman·Netanel Lindner·Mark Rudner·Erez Berg
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Abstract

We consider two-dimensional periodically driven systems of fermions with particle-hole symmetry. Such systems support non-trivial topological phases, including ones that cannot be realized in equilibrium. We show that a space-time defect in the driving Hamiltonian, dubbed a ``time vortex,'' can bind $\pi$ Majorana modes. A time vortex is a point in space around which the phase lag of the Hamiltonian changes by a multiple of $2\pi$. We demonstrate this behavior on a periodically driven version of Kitaev's honeycomb spin model, where $\mathbb{Z}_2$ fluxes and time vortices can realize any combination of $0$ and $\pi$ Majorana modes. We show that a time vortex can be created using Clifford gates, simplifying its realization in near-term quantum simulators.

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Gilad Kishony, Ori Grossman, Netanel Lindner, Mark Rudner, Erez Berg. 2024-10-22. Topological excitations at time vortices in periodically driven systems. https://doi.org/10.1038/s41535-025-00745-8

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